Backpack blower

ABSTRACT

A backpack blower comprising a blower which has an air intake opening, a backpack frame which is used to support the blower on the back of a user, and a back pad that is coupled to the backpack frame and contacts the back of the user. The back pad is composed of a cushion material and has a back surface contacting the back of the user and an opposite surface. The air intake opening communicates with at least a portion of the opposite surface, so that the air intake noise of the blower can reach at least the portion of the opposite surface.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a backpack blower in which a blower is mounted on a backpack frame. This application claims priority to Japanese Patent Application No. 2006-171065, filed Jun. 21, 2006, the entire contents of which is hereby incorporated by references.

2. Description of the Related Art

Backpack blowers are machines that are suitable for blowing cut grass or fallen leaves. During the operation of a backpack blower, noise is generated by various causes; one such cause is the air intake noise of the blower that is mounted on the backpack frame. Naturally, it is desirable that this air intake noise be as small as possible.

Accordingly, a technique has been proposed for the purpose of reducing the air intake noise (see US-2002-0060107-A1) in which a hollow space is formed in the backpack frame, and small holes are formed in a wall that constitutes the hollow space and that faces the air intake opening of the blower.

SUMMARY OF THE INVENTION

The present invention employs a construction that is distinguished from the conventional technique described above in order to achieve a great reduction in air intake noise.

In the embodiment of the present invention, the backpack blower comprises a blower which has an air intake opening, a backpack frame which is used to support the blower on the back of a user, and a back pad that is coupled to the backpack frame and contacts the back of the user. The back pad is composed of a cushion material. The back pad comprises a back surface contacting the back of the user and a surface (hereinafter referred to as “opposite surface”) opposite the back surface. Here, the air intake opening communicates with at least a portion of the opposite surface, so that the air intake noise of the blower can reach at least the portion of the opposite surface. As such, at least a portion of the opposite surface faces the air intake opening and communicates with the air intake opening.

In the present invention, the back pad absorbs the shock of the vibration and load that are transmitted to the back of the user from the backpack frame, and protects the user. In addition, the back pad also has a noise attenuating action. Specifically, the air intake noise of the blower reaches at least the portion of the opposite surface and is attenuated by the back pad composed of a cushion material. As a result, noise created by the operation of the blower is reduced. In the present invention, the back pad has a noise reducing action in addition to an intrinsic shock-absorbing action. Accordingly, the present invention has a rational construction with no waste.

In one embodiment, the backpack blower may have at least one partition between the air intake opening and the opposite surface, and this at least one partition may have numerous holes that allow the air intake noise of the blower to pass through. In this case, the air intake noise diffuses or expands immediately after passing through the numerous holes, thereby improving the noise eliminating effect. Furthermore, even in cases where a fluctuation in air pressure is generated in the air that is taken in from the air intake opening, the intake and outlet of air is performed via the numerous holes, and the flow or air is adjusted. Consequently, the generation of noise is prevented.

In another embodiment, a first partition and second partition may be provided between the air intake opening and the opposite surface, and each of these partitions may have numerous holes that allow the air intake noise of the blower to pass through. In this case, the air intake noise diffuses or expands immediately after passing through the numerous holes in the first partition, and again diffuses or expands immediately after passing through the numerous holes in the second partition, thereby improving the noise eliminating effect.

In one embodiment, the at least one partition described above may be an air intake guide which has a smooth raised part oriented toward the air intake opening in the central part. In this case, since the partition has this raised part, the air intake efficiency of the blower is improved.

In one embodiment, the backpack blower may have a ventilation cover that prevents the intake of foreign matter into the air intake opening, and the ventilation cover and air intake guide may be formed as an integral unit. This facilities the installation and removal of the ventilation cover and air intake guide on or from the backpack blower.

In one embodiment, the unit described above may be supported on the backpack frame. If this is done, an attachment method can be used which is simpler than the method used in cases where the unit is supported on the blower. The reason for this is that the vibration of the backpack frame is far smaller than the vibration of the blower itself.

Furthermore, since the blower is a working member that generates noise, the present invention can also be defined as a backpack working machine comprising a working member that generates noise, a backpack frame that is used to support this working member on the back of a user, and a back pad that is coupled to the backpack frame and contacts the back of the user, and is a pad that is composed of a cushion material and has a back surface contacting the back of the user and an opposite surface, wherein the working member communicates with at least a portion of the opposite surface so that noise generated by the working member is eliminated by the back pad.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the use state of the backpack blower according to one embodiment of the present invention;

FIG. 2 is a longitudinal sectional left side view of the central portion in the left-right direction of the main body part of the backpack blower shown in FIG. 1;

FIG. 3 is a perspective view of the backpack frame and air intake assist unit shown in FIG. 2; and

FIG. 4 is a sectional view showing a modification of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described below with reference to the attached figures.

FIG. 1 depicts a backpack blower 1 suitable for blowing away fallen leaves L, cut branches and leaves, and the like.

The backpack blower 1 of the present embodiment comprises a centrifugal blower 5 as a blower, and a backpack frame 4 that is used to support this blower 5 on the back of an operator U. The backpack frame 4 has a pair of backpack straps, i.e., left and right backpack straps 3, 3. For example, an internal combustion engine 6 such as an air-cooled two-cycle gasoline engine or the like is mounted on the backpack frame 4 as a motor that is used to drive the blower 5. An air discharge pipe 9 is connected to the air discharge opening 5a of the blower 5 via an elbow pipe 7 and a bellows hose 8.

The operator or user U carries the backpack frame 4 on the back via the left and right backpack straps 3, 3, and grips a grip part 10 that is attached to the base end part of the air discharge pipe 9. While controlling the orientation of the air discharge pipe 9 and the internal combustion engine 6, the user can efficiently perform the work of blowing away fallen leaves L or the like by blowing a large quantity of air that is discharged from an air discharge opening 9 a at the tip end of the air discharge pipe 9.

As shown in FIGS. 2 and 3, the backpack frame 4 comprises a plate-form upright part 11, and a plate-form seat part 12 that extends substantially horizontally to the rear of the worker U from the lower part of the upright part 11. The backpack frame 4 is thus formed substantially in an L shape as seen in a left side view. For example, the backpack frame 4 can be integrally formed by a method such as blow molding or the like using a plastic that has light weight and good durability. Furthermore, the backpack frame 4 may have ribs, indentations and projections in the manufactured structure, or the like for the purpose of reinforcement. In FIG. 3, however, the backpack frame 4 is drawn with a simple shape in order to simplify the graphic representation.

As better seen in FIG. 2, a blower unit 14, in which the blower 5 and internal combustion engine 6 are integrated, is supported in an anti-vibration manner on the backpack frame 4. An anti-vibration member 15 composing compression coil springs, rubber blocks, or the like is disposed between the blower unit 14 and backpack frame 4. Accordingly, the vibration that occurs during the operation of the blower unit 14 is not directly transmitted to the backpack frame 4. In the blower unit 14, the centrifugal fan 16 of the blower 5 is operatively connected to the output shaft 17 of the internal combustion engine 6. The air intake opening 18 of the blower 5 faces the back surface 11 r of the upright part 11 with an air intake space S of specified dimensions provided therebetween. An intake air flow channel 19 is formed in the seat part 12 so that intake air from below can also be ensured by the blower 5.

A back pad 20, which contacts the back of the user U, is linked to the front surface 11 f of the upright part 11. This back pad 20 is formed from a plate-form cushion material that has a good shock-absorbing and sound-absorbing properties. For example, urethane foam formed by compression-molding expanded urethane can be used as the material of the back pad 20.

The back pad 20 comprises a back surface (front surface) 20f contacting the back of the user U, and an opposite surface (rear surface) 20 r. A spacer part 21, which rises toward the upright part 11, is around the periphery of the back pad 20, and a contact part 22, which contacts the upright part 11, is formed around the entire circumference of the spacer part 21. In the back pad 20, mainly the contact part 22 is fastened to the upright part 11. This fastening may be accomplished by fastening parts such as screws or the like, or may be accomplished by bonding using an adhesive agent. In the state in which the back pad 20 is attached to the upright part 11, a space part (second space part described later) 23 is formed by the action of the spacer part 21 between the opposite surface 20 r and the front surface 11 f of the upright part 11.

The back pad 20 comprises a reinforcing spacer part 24 in a position on the lower part of the opposite surface 20 r. The reinforcing spacer part 24 protrudes to a position contacting the front surface 11 f of the upright part 11, and is fastened to the front surface 11 f. When the user U carries the main body part of the backpack blower 1 on the back, the lower part of the back pad 20 is firmly pressed against the back of the worker U by the load of the backpack blower 1. However, by virtue of providing of the reinforcing spacer part 24, there is no crushing of the second space part 23. For example, the installation position of the reinforcing spacer part 24 is a position that causes no blockage of numerous holes 26 in a second partition 25 described later, such as the left and right sides of the lower part of the opposite surface 20 r, or the like.

An air intake guide 27, which is used to increase the efficiency of the intake of air into the air intake opening 18, is attached to the backpack frame 4. As will be described later, the air intake guide 27 also acts as a first partition that is used to reduce or eliminate noise. The air intake guide 27 is positioned between the opposite surface 20 r of the back pad 20 and the air intake opening 18, and faces the air intake opening 18. The air intake guide 27 comprises a smooth raised part 28 oriented toward the air intake opening 18 in the central part of a circular main body. A space part 29, which includes the second space part 23, is disposed between the air intake guide 27 and the opposite surface 20 r of the back pad 20.

Furthermore, the air intake guide 27 may be configured with numerous holes (small holes) 30 that allow the air intake noise of the blower 5 to pass through. The size of each hole 30 is set at a size in which the air intake noise can be effectively reduced eliminated by being diffused or expanded immediately after passing through the hole 30. It is desirable that each hole 30 has no corner portions and be configured in a circular, elliptical, or other non-covered shape. A plurality of claws 31 (only one is shown in FIG. 2) are formed on the front surface of the air intake guide 27 as attachment parts for attaching to the backpack frame 4. These claws 31 engage with claw receiving holes 32 formed in the second partition 25. The air intake guide 27 can be formed using a plastic.

The second partition 25 used to reduce or eliminate noise is disposed between the air intake guide 27 and the opposite surface 20 r of the back pad 20. The second partition 25 is formed in a circular shape with a small thickness in substantially the central portion of the upright part 11 as one part of the upright part 11. The second partition 25 partitions the space part 29 between the air intake guide 27 and the back pad 20 into a first space part 33 on the side of the air intake guide 27, and the second space part 23 on the side of the back pad 20. The numerous holes (small holes) 26 that are used to allow the air intake noise of the blower 5 to pass through are formed in the second partition 25. These holes 26 are formed in positions facing the numerous holes 30 formed in the air intake guide 27. The size of each hole 26 is also set such that the air intake noise can be effectively reduced or eliminated by being diffused or expanded immediately after passing through the hole 26. Each hole 26 is preferably round, elliptical, or of another non-cornered shape.

As shown in FIG. 3, a ring-form spacer 34 is integrally formed on the second partition 25, on the surface located on the side of the air intake guide 27. The air intake guide 27 is concentrically disposed on the ring-form spacer 34, and is fastened to the second partition 25. The ring-form spacer 34 defines the first space part 33 between the air intake guide 27 and the second partition 25. The claw receiving holes 32 are disposed in the second partition 25 at intervals in the circumferential direction of the ring-form spacer 34. The respective claws 31 of the air intake guide 27 engage with the respective claw receiving holes 32.

As shown in FIG. 2, a collar-form grid 36, which has numerous ventilation holes 35 in the circumference, is disposed in the air intake space S. The collar-form grid 36 is a ventilation cover which is used to prevent foreign matter such as fallen leaves, small branches, or the like from being taken into the air intake opening 18 from the air intake space S. The collar-form grid 36 is disposed concentrically with the air intake opening 18 so that the ventilation holes 35 are positioned on the outside in the radial direction of the air intake opening 18. The collar-form grid 36 can also be formed using a plastic.

In the present embodiment, the air intake guide 27 and the collar-form grid 36 are formed as an integral unit, and are formed as an air intake assist unit 13, as is shown in FIG. 3. Accordingly, the work of attaching the collar-form grid 36 and air intake guide 27 to the backpack frame 4 is facilitated. The air intake guide 27 and collar-form grid 36 may be integrated by connecting separately formed parts, or may be formed as an integral unit from the beginning.

In the present embodiment, the air intake assist unit 13 is supported on the backpack frame 4. Conversely, the air intake assist unit 13 can also be supported on the blower 5. However, if the air intake assist unit 13 is supported on the backpack frame 4, an attachment method can be used, that is simpler than the method used in cases where the unit is attached to the blower 5. The reason is that the vibration of the backpack frame 4 is far smaller than the vibration of the blower 5 due to the action of the anti-vibration member 15.

Furthermore, in regard to the method used to attach the air intake assist unit 13 to the backpack frame 4, fastening parts such as screws or bonding using an adhesive agent may be used in addition to the engagement of the claws 31 and the claw receiving holes 32.

In the backpack blower 1, as is shown in FIG. 2, the air intake opening 18 of the blower 5 and at least a portion of the opposite surface 20 r of the back pad 20 communicate with each other, so that the air intake noise of the blower 5 can reach at least the portion of the opposite surface 20 r. In concrete terms, the air intake opening 18 communicates with at least the portion of the opposite surface 20 r via the air intake space S, the numerous holes 30 formed in the air intake guide (first partition) 27, the first space part 33, the numerous holes 26 formed in the second partition 25, and the second space part 23. Accordingly, the air intake noise of the blower 5 reaches at least the portion of the opposite surface 20 r via the first space part 33 and second space part 23, and is attenuated or eliminated by the back pad 20 that comprises a cushion material. As a result, the noise generated by the operation of the blower 5 is reduced.

Moreover, the back pad 20 absorbs the shock of the vibration or load that is transmitted to the back of the user U from the side of the backpack frame 4, and protects the user U. In addition, the back pad 20 also has the action of causing attenuation of the noise. Accordingly, there is no need to install a special sound-absorbing material in addition to the back pad 20; consequently, the backpack blower is rational, with no waste in the construction, and reduction in cost.

For the present embodiment, in addition to the sound-absorbing action of the back pad 20, the air intake guide 27 used as a first partition, and the second partition 25, also have a noise reducing or eliminating functionality, so that the noise-attenuating effect is greatly improved. In concrete terms, the air intake noise of the blower 5 is caused to diffuse or expand by the first space part 33 immediately after passing through the numerous holes (small holes) 30 of the air intake guide 27. As such, the noise is first attenuated at this point in time. Furthermore, the air intake noise is caused to expand by the second space part 23 immediately after passing through the numerous holes 26 of the second partition 25; accordingly, the noise is further attenuated at this point in time. The air intake noise that is thus attenuated at a plurality of stages is finally absorbed by the back pad 20. If necessary, the expansion and flow adjustment of the air intake noise can be repeated a number of times by increasing the partitioning of the space part 29 which in turn would provide a greater noise reducing or eliminating effect.

Furthermore, in the present embodiment, since the numerous holes 30 and 26 are formed in the air intake guide 27 and second partition 25, the following advantage is obtained: namely, even in cases where air pressure fluctuations occur in the air that is taken in from the air intake opening 18, the intake and outlet of air is performed by the numerous holes 30 and 26, the flow is adjusted, and the generation of noise is prevented.

FIG. 4 shows a modification of FIG. 2. Here, the first difference from the example shown in FIG. 2 is that the second partition 25 is eliminated. Specifically, in the upright part 11 of the backpack frame 4, an opening 40 that is larger than the air intake opening 18 of the blower 5 is formed concentrically in a position facing the air intake opening 18. In this case, only an air intake guide 41 is present as a first partition for partitioning between the air intake opening 18 and the back pad 20. A space part 42 is present between the air intake guide 41 and the opposite surface 20 r of the back pad 20. As in the example shown in FIG. 2, the air intake guide 41 has a smooth raised part 39 oriented toward the air intake opening 18 in the central portion, and has numerous noise-eliminating holes (small holes) 43 that allow the air intake noise to pass through.

In the embodiment shown in FIG. 4, the air intake opening 18 communicates with at least a portion of the opposite surface 20 r via the numerous holes 43 formed in the air intake guide 41, and the space part 42. Accordingly, the air intake noise of the blower 5 reaches at least the portion of the opposite surface 20 r via the numerous holes 43 and space part 42, and is attenuated by the back pad 20 that comprises a cushion material. As a result, the noise that is generated by the blower 5 is reduced. Since the air intake noise is caused to diffuse or expand by the space part 42 immediately after passing through numerous holes 43, the noise reducing or eliminating effect is greatly improved.

Furthermore, this embodiment includes an air intake assist unit 45 in which the air intake guide 41 and collar-form grid 44 are integrated is supported on a volute case 46 of the blower 5. In order to allow attachment to the volute case 46, insertion parts 47 for fastening screws 48 are integrally formed in the collar-form grid 44. In correspondence with these, female screw holes 49 which receive the fastening screws 48 are formed in the volute case 46. Furthermore, the shape of the collar-form grid 44 also differs from that used in the previous embodiment of FIG. 2.

As is clear from the above embodiments, an advantage of the present invention is the provision of air intake noise attenuating properties in a backpack blower configuration that has been conventionally used to protect users from vibration. Furthermore, another feature is the provision of at least one partition having numerous holes with noise-eliminating effect, and, if possible, a plurality of such partitions, are disposed between the air intake opening and the back pad.

Although embodiments of the apparatus embodying the present invention have been depicted and disclosed in the foregoing detailed description, it will be appreciated that the present invention is not limited to the disclosed embodiments and the modifications are possible without departing from the spirit and scope of the invention as set forth and defined by the attached claims.

For example, the blower 5 may be defined as a working member that generates noise; so that the present invention may be defined as a backpack working machine comprising a working member 5 that generates noise, a backpack frame 4 that is used to support the working member 5 on the back of a user U, a back pad 20 that is coupled to the backpack frame 4 and contacts the back of the user U, and is composed of a cushion material and has a back surface 20f and an opposite surface 20 r, wherein the working member 5 communicates with at least a portion of the opposite surface 20 r so that the noise generated by the working member 5 is attenuated by the back pad 20. 

1. A backpack blower comprising: a blower having an air intake opening; a backpack frame configured to support the blower on the back of a user; and a back pad that is coupled to the backpack frame and is configured to contact the back of the user, the back pad comprising a cushion material and having a back surface contacting the back of the user and an opposite surface, wherein the air intake opening communicates with at least a portion of the opposite surface so that the air intake noise of the blower can reach at least the portion of the opposite surface.
 2. The backpack blower according to claim 1, wherein at least one partition is disposed between the air intake opening and the opposite surface; and the at least one partition has numerous holes that allow the air intake noise of the blower to pass through.
 3. The backpack blower according to claim 1, wherein a first partition and a second partition are disposed between the air intake opening and the opposite surface; and each of the partitions includes numerous holes that allow the air intake noise of the blower to pass through.
 4. The backpack blower according to claim 2, wherein the at least one partition is an air intake guide which has a smooth raised part oriented toward the air intake opening in the central part.
 5. The backpack blower according to claim 4, comprising a ventilation cover which prevents foreign matter from being taken into the air intake opening, wherein the ventilation cover and the air intake guide are formed as an integral unit.
 6. The backpack blower according to claim 5, wherein the unit is supported on the backpack frame.
 7. A backpack blower comprising: a blower having an air intake opening; a backpack frame configured to support the blower on the back of a user; and a back pad that is coupled to the backpack frame and is configured to contact the back of the user, the back pad being composed of a cushion material and having a back surface contacting the back of the user and an opposite surface, wherein at least a portion of the opposite surface faces the air intake opening and communicates with the air intake opening.
 8. The backpack blower according to claim 7, comprising at least one partition between the air intake opening and opposite surface, wherein the at least one partition has numerous holes that allow the air intake noise of the blower to pass through.
 9. The backpack blower according to claim 7, wherein a first partition and a second partition are disposed between the air intake opening and the opposite surface; and each of the partitions includes numerous holes that allow the air intake noise of the blower to pass through.
 10. The backpack blower according to claim 8, wherein the at least one partition is an air intake guide which has a smooth raised part oriented toward the air intake opening in the central part.
 11. The backpack blower according to claim 10, comprising a ventilation cover which prevents foreign matter from being taken into the air intake opening, wherein the ventilation cover and the air intake guide are formed as an integral unit.
 12. The backpack blower according to claim 11, wherein the unit is supported on the backpack frame.
 13. A backpack working machine comprising: a working member that generates noise; a backpack frame which is used to support the working member on the back of a user; and a back pad that is coupled to the backpack frame and is configured to contact the back of the user, and is a pad that is composed of a cushion material and has a back surface contacting the back of the user and an opposite surface, wherein the working member communicates with at least a portion of the opposite surface so that the noise generated by the working member is attenuated by the back pad. 